The present invention relates to electronic power converters and more particularly to a circuit for sensing
the output current of such converters for control purposes
In power converters, it is necessary in many cases to accurately sense the output current of the converter for either measurement or control purposes A simple way to accomplish this objective is to connect a shunt in series with the output, but this straight-forward method suffers from several disadvantages. These include considerable bulk and power dissipation when high currents are measured and the incapability of providing an isolated current signal This last problem is particularly significant in the case of isolated converters where the control circuit is located in the primary side and galvanic connection between the primary and the secondary side is not allowed.
Although current sensing circuits based on magnetic amplifiers have long been known in the art, these circuits are complex, bulky and expensive and generally unsuitable for use in high density converters.